HIV-1 Nef upregulates CCL2/MCP-1 expression in astrocytes in a myristoylation- and calmodulin-dependent manner
HIV-1 Nef upregulates CCL2/MCP-1 expression in astrocytes in a myristoylation- and calmodulin-dependent manner
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DOI：
10.1242/jcs.03231
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发表时间：
2006-11-01
影响因子：
4
通讯作者：
Erfle, Volker
中科院分区：
文献类型：
--
作者：
Lehmann, Michael H.;Masanetz, Sabine;Erfle, Volker
hiv相关痴呆（HAD）与单核细胞渗入大脑有关。辅助HIV-1阴性因子（Nef）蛋白，可调节多种信号通路，组成性地存在于持续感染的星形胶质细胞中。我们证明单核细胞对表达nef的星形细胞U251MG细胞的细胞培养上清有趋化反应。利用蛋白质阵列，我们鉴定出CC趋化因子配体2/单核细胞趋化蛋白-1 （CCL2/MCP-1）是介导这种现象的潜在趋化因子。核糖核酸酶保护实验、RT-PCR和ELISA进一步证实了Nef对CCL2/MCP-1的上调作用。通过使用抗CCL2/MCP-1的中和抗体和ccr2缺陷单核细胞，我们证实CCL2/MCP-1是能够吸引单核细胞的nef表达星形胶质细胞分泌的唯一因子。此外，我们发现Nef诱导的CCL2/MCP-1表达依赖于Nef的肉豆蔻酰化部分，需要功能性钙调蛋白。总之，我们认为nef诱导的星形胶质细胞中CCL2/MCP-1的表达有助于单核细胞向大脑的浸润，从而促进HAD的进展。
HIV-associated dementia ( HAD) correlates with infiltration of monocytes into the brain. The accessory HIV-1 negative factor (Nef) protein, which modulates several signaling pathways, is constitutively present in persistently infected astroctyes. We demonstrated that monocytes responded with chemotaxis when subjected to cell culture supernatants of nef-expressing astrocytic U251MG cells. Using a protein array, we identified CC chemokine ligand 2/monocyte chemotactic protein-1 (CCL2/MCP-1) as a potential chemotactic factor mediating this phenomenon. CCL2/MCP-1 upregulation by Nef was further confirmed by ribonuclease protection assay, RT-PCR and ELISA. By applying neutralizing antibodies against CCL2/MCP-1 and using CCR2-deficient monocytes, we confirmed CCL2/MCP-1 as the exclusive factor secreted by nef-expressing astrocytes capable of attracting monocytes. Additionally, we showed that Nef-induced CCL2/MCP-1 expression depends on the myristoylation moiety of Nef and requires functional calmodulin. In summary, we suggest that Nef-induced CCL2/MCP-1 expression in astrocytes contributes to infiltration of monocytes into the brain, and thereby to progression of HAD.